Project Summary/Abstract Smokers partnered with other smokers (i.e., dual-smoker couples) represent ~2/3 of all smokers. Dual- smoker couples (DSCs) are less likely to try to quit smoking and more likely to relapse during a quit attempt, reducing overall smoking cessation rates and representing a high-risk clinical population. Despite their high prevalence and risk for persistent smoking, however, there are limited data on the smoking cessation interventions among DSCs. Building on previous research that suggests financial incentive treatments (FITs) are effective at increasing motivation to quit and quit rates in general, the proposed pilot study will systematically explore using two variants of FIT with DSCs. Specifically, we will test a traditional FIT (i.e., targeting one individual of a couple) as well as a dyadic variant of FIT?targeting both members of a couple with simultaneous financial incentives. Determining the efficacy of FIT (single or dyadic) for DSCs would require a randomized controlled trial (RCT) and the proposed pilot study will generate critical preliminary data in three domains. First, we will examine the feasibility of a novel modified dyadic version of FIT for DSCs that targets both members of the dyad (dyadic FIT), comparing it to standard FIT and a no-FIT active control group. Second, we will use the pilot study to generate a range of effect size estimates to inform a future RCT of FIT in DSCs. Finally, we will examine individual and dyadic factors that may serve as mechanisms of behavior change for FIT interventions in DSCs. We address these questions in a three-group pilot RCT. In all conditions, both individuals in the couple will have access to standardized active treatment (i.e., Nicotine Replacement Therapy, a 4-week manualized educational program). In each couple, the person who first contacts the cessation program will be designated the target. In the control condition, no individual will receive financial incentives. In the single-target FIT condition, the target will additionally receive financial incentives for program attendance and abstinence at follow-up. In the dyadic FIT condition, both members of each couple (target + partner) will receive financial incentives for program attendance and smoking abstinence. The primary feasibility outcome is % of participants who complete all sessions of the study; the primary tolerability outcomes are the % of participants opting to discontinue study participation due to study procedures. Primary outcomes are program completion and point-prevalence abstinence at 3 months. Potential mechanisms of behavior change include both individual factors (e.g., change in self-efficacy and motivation) and dyadic factors (e.g., joint quitting, partner support). Preliminary data on feasibility, efficacy, and mechanisms of behavior change will allow us to determine whether the dyadic format for FIT is viable for smoking cessation in DSCs. The findings will be directly used to inform future RCTs testing FIT to promote quitting in this treatment refractory population.